shore



Sept; 6,1932. w, E SHORE 1,875,397

' ROTARY MACHINE I Filed March 26. '1930 5 Sheets-Sheet 1 ATTORNEY Sept. 6, 1932. w, SHQRE 1,875,397

ROTARY MACHINE Filed March 20. 1950 3 Sheets-Sheet 2 N I is I 4* 47 1 7 28 rs 21 INVENTOR 51 Wi/IiamE. Shore.

ATTORNEY Patented Sept. 6, 1932 UNITED STATES PATENT OFFICE WILLIAM E. SHORE, OF WEST NEW BRIGHTON, NEW YORK no'rAnY MACHINE lpplication filed March 20, 1930, Serial No. 437,583, and in Canada April 5, 1929.

The principal objects of this invention are to devise an extremely compact self-contained rotary machine which will operate continuously at a high degree of efiiciency at very high speed and which will not be detri- I mentally subject to Wear and which will be particularly eflective in the preparing of liquid hydrocarbons for combustion and also useful for other purposes.

A further and very important ob'ect of the present invention is to enhance the efliciency of the type of rotary compressor or vacuum machines wherein a single vane operates within a rofiled cylinder.

A further 0 ject of the invention is to incorporate in a machine of this type an oil pumping element which will utilize the peculiar motions set up therein in operation to pump a positive supply of oil which may be absorbed by the'machine or be directed to an independent point as desired depending on the character of the work the machine is called upon to perform.

A still further and important object of the present invention is to obviate the serious difficulties met with in the close-coupling of a rotary pumping machine and an electric power element incidentto the leakage of the mediums being handled and overheating of the motor whereby the motor will not only be adequately cooled and ventilated but will be very definitely protected from contamination by the handled medium. 7 The principal feature of the invention consists in the novel construction and arrangement ofparts wherein a single vane pumping element or machine which is directly incorporated in a driving motor or element.

A still further and important. feature of the invention resides in the novel arrangement of ports and passages whereby the roller member efiects the displacement of oil or other fluid medium.

A still further feature consists in the novel construction whereby the escape of oil from the pump into the driving motor is avoided.

Another andimportant ieature consists in the novel construction and" arrangement of parts whereby an effective circulation of air through the motor is maintained to efi'ect the cooling'thereof.

In the drawings, Fi ure 1 is an elevational part sectional view 0 a complete unit cong structed in accordance with this invention.

Figure 2 is a cross section taken on the line 2-2 of Figure 1 showing the arrangement of the vane and roller support.

Figure 3 is a cross section similar to Figure 2 on the line 3-3 of Figure 1 showing the arrangement of the parts with the vane in a position at right angles to Figure 2.

Figure 4 is a cross section taken on the line 4--4 of Figure 1 showing the manner in which the oil escaping past the packing gland is returned to the ump.

Figure 5 is a mid-sectional detail of the closed end of the pump showing the supporting roller and an arrangement of ports for utilizing the action of the roller support in the slot for pumping fluids, and illustrating the various ports in register.

Figure 6 is a cross-sectional view taken on the line 66 of Figure 5. v I

Figure 7 is a cross sectional view similar to Figure 5 but showing the ports out of register.

Figure 8 is a mid-sectional view taken on the line 88 of Figure 7 showing the slot ports out of register with the stationary ports in the casing.

Figure 9 1s a perspective detail of a vane element constructed invention.

The present invention has been devised in accordance with this with a view to providing a single vane type the motor shaft 5 extending axially through the boss 2.

The outward end of the casing 1 is bored to provide the profiled cylinder surface 6,

the axis of which is spaced parallelly from the axis of the motor shaft 5.'

The cylinder surface is formed in the'manner set forth in my United States Patent No.

1,742,731 of January 7, 1930, and need not be described in detail herein except to say that the cylinder. wall is profiled in order to co-operate with and provide for the accommodation of the single vane member in its rotation in the cylinder so that the wall will conform to the path defined by the extremities of the single vane and thus maintain a uni form seal therebetween.

The rotor 7 is partly recessed into the counterbore 8 in the inner wall of the casing 1 which is concentric with the-motor shaft and the walls of this counterbore form a substantial seal with the engaging surfaces of the rotor.

The rotor is provided with a tubular or sleeve extension 9 which snugly encircles the shaft 5 of the motor and the end of the motor shaft may be threaded at 10 into a corresponding threaded inner portion of the rotor sleeve or may be secured thereto in any other well known manner as by keying and pressing thereon. l

A roller bearing 11 snu ly encircles the rotor sleeve 9 and lfits snugly within an annular ring 12 which may be pressed, threaded or otherwise secured in the counterbore 13 in the boss extension 2'leading from the bottom of the counterbore 8. The annular ring is formed with an inturned flange 14, the

outer face of which forms a substantial seal with the adjacent face of 'the rotor 7.

The rotor is thus supported onthe motor shaft in a rigid unit therewith and the bearing 11 serves to support the working end of the motor shaft as well as the rotor in a very compact and eflicient manner. I

A sin le vane 15 is provided which is a snug sliding fit in the transverse slot 16 of the rotor. 7

mately engage the outer face of the rotor to form a substantial seal therewith and carried by the hub portion 17 is a concentric guide disc or flan e '18 which presents a smooth bearing sur ace on either side.

The outer side of the guide disc 18 is ada tt ed to intimately engage the wall 19 o a counterbore formed in the end closure member 20 of the cylinder and an annular bear ing ring 21 is secured at its outer periphery in the counterbore 22 of the cylinder casing by the inwardly projecting annularflange 22 of the closure member. The annular bearing flange thus secured extends inwardly and engages the inward side of the disc 18.

The disc is thus definitelyheld against lateral displacement but may be displaced radially in a direction at-true right angles to the axis of the cylinder or shaft, and in this way the outer ends of the vane will be definitely maintained in true parallel relation to the surface of the cylinder wall 6 with which the co-operate.

hub extension 23 is provided on the outer side of the uide' disc 18 which extends into a recess 24 in the closure member 20 and a guide slot 25 is formed therein which extends in true right angular relation to the vane 15.

The walls of said slot are spaced parallelly apart and are connected at the ends by the curved walls 26, the radius of which is equal to one half the distance between the spaced guide walls.

A short stub shaft 27'is secured firmly and non-rotatably in the closure member 20 in axial alignment with the cylinder axis, which as previously stated, is parallelly offset from theaxis of the motor shaft.

The inner end of the stub shaft 27 extends into the guide slot 25 and is preferably faced to intimately engage the disc 18 centrally and has mounted thereon a roller bearing 28, the outer ring of which intimately en ages the parallelly spaced walls of the gui e slot 25 in a rolling contact and very definitely positions the vane in a true concentric position in the cylinder. In this way when the rotor is being driven and the vane rotating in the cylinder, the vane will, by reason of the cooperation of the guide slot walls 'with the rigidly mounted roller, be constantlymoved thereby to a neutral position and the vane will be obtainedwhich will be unidirectional disc 18 in that the side walls thereof rotatably and slidably engage the adjacent surfaces of,

In'the construction illustrated in Figures 5 to 8, the guide disc 29 is formed of a width considerably greater than the previously described guide disc 18 and the counterbore 30- of the head member is made correspondingly deeper in order to accommodate the larger disc, In this latter construction the same condition obtains as in the case of the guide the counterbore wall 19 and the annular bearing ring 21 in snug guiding contact.

The guide slot 25' in this case is formed in thedisc which is the equivalent of the arrangement shown in FiguresQ and 3.

At each end of the guide slot 25' is formed a port 31 which opens outwardly toward the inner face of the counterbore wall 19 and these ports. 31 are adapted to register successively with the-arc-shaped fixed ports32 and 33 in the closure'member 20;

As indicated in. Figures 6 and 8 it will be seen that the arc-shaped orts are semi-circular and terminate at t eir extremities a short distance from each other and are preferably confined to either side of a line passing through the axes of the cylinder and the motor shaft in order to obtain the maximum efiiciency and proper timing of the inlet and outlet ports with the ports 31 as the disc 29 rotates;

The pdrt 32 may be connected by suitable piping 34 toa supply tank of oil or other mediumwhich it is desired to pump and a pipe 35 may extend from the port 33 and conduct the oil to any desired point either within the machineto be utilized therein for lubricating purposes or may be introduced in regulated quantities into the intake 1' of the pump, or the pipe 35 may lead to points independent of the pump.

It will readily be understood on reference to the drawings that a very positive pumping action will be set up by the relative movement of the guide slot walls and guide roller, the latter acting in the capacity of a piston which alternately displaces the oil from first one end of the guide slot and then the other as the respective ends and ports 31 thereof are carried past the discharge port 33. It will be noted that as each of the ports 31 are moving past the-inlet arc-shaped' port 32;"the

- guide roller will be receding in the slot relative to the said port 31, while at the same time it will be relatively advancing toward the opposite port 31 which is re ister with the discharge-port 33 so thata de nite supply of oil will be handled each rotation of the machine.

in view of the close-coupled relation of the motor and pumping elements it is imperative that the windings of the motor be protectedin an adequate manner from contact with the oil or medium handled by the pump and it is furthermore desirable to make special provision for the adequate cooling of the motor in order to obtain the maximum degree of ef-' ficiency.

For this purpose an annular packing ring 37 is provided which snugly encircles a short sleeve portion 39 arranged between the bearing 11 and a centrifugal impeller member 40 arranged on the motor shaft 5; The packing ring 37 is formed with a tubular extension 41 a which extends into an axial bore 42 in the easing hub 2 either pressed therein or threaded as desired. A pair of spaced annular grooves 43 and 44 are formed in the inner encircling wall of the packing ring and the inner groove 44 carries a suitable packing material 44 which snugly engages contact. a I

The-groove 43 forms a circumferential re cess encircling the sleeve 39 on the outward side of the packing ring and any oil or vapour which might possibly find egress past the the sleeve 39 in sealing packing ring will enter the move recess 43. v

A duct 43 leads from the ower portion of the groove 43 to a passage 45 extending circumferentially of the packing ring 37, (see Figure 4) and connects with a passage 46 in the pump casing 1 which leads to a passage 47 which conducts the oil directly into the intake 1 of the cylinder. In this way the groove recess 43 is constantly under the vacuum infiuence of the intake and oil or vapour finding its way thereto will be immediately drawn therefrom back into the machine.

It will be further noted that there will be a constant tendency for atmospheric air to enter the groove 43 fromthe motor side be tween the sleeve 39 and the outer wall 48 of the groove 43 due to the vacuum condition existing in the latter and this will have the further desirable effect of constantly cleansing this portion of the sleeve 39 preventing any possibility of oil working its way along the same toward themotor, and there is no possibility of the motor becoming contaminated with oil.

A plurality of openings 50 are arranged in the outer wall of the motor casing in direct. radial alignment with the impeller member 40. A second series of openings 51 are formed in the end wall of the motor casing encircling the tubular extension thereof and an annular within the motor casingagainst the annular shoulder 53 and forms a partition between the sets of openings 50 and 51. The inner peripherv of the annular bafile disc 52 is spaced from the sleeve 39 of the shaft 5 and forms an annular passage 54 through which air from the openings 51 passes to the impeller.

With this arrangement when the motor is operating the impeller thrusts air out through the openings 50 and draws a cool supply in through the openings 51, the 'disc 52 serving to direct the incoming supply to the central portion of the impeller so that a very effective circulation is obtained and the efficient operating temperature of the motor will be maintained.

A machine such as described will be found to present many advantages particularly due to its ability to operate continuously at extremely high speed.

The'vane is at all times definitely support ed in a neutral position against metallic contact with the-cylinder wall by the rolling sup.- port described which absorbs the very heavy .thrust with the minimum of friction and consequently wear is reduced to a minimum and this reduction of friction in the working parts is transformed into work so that a speed of operation is economically obtained which was hitherto impossible. I

It is therefore possible to subject a fluid medium to instantaneous changes of pressure and to raise its temperature so rapidly by compression that substantially all the generated heat is maintained in the'treated me-' dium and little or no heat is transferred to the surrounding body of the pump in a manner which closely approaches the ideal adiabatic condition. This condition is further enhanced due to the enormous volume of which the pump is capable of handling relative to its size and due to speed alone so that the contact area presented by the pump to the medium will be extremely small.

' In this way the energy consumed in the driving machine may be converted or transformed with very small loss into the prepar ing of the liquid hydrocarbon or fuel to a condition of heat and vapour tension on the discharge, and a decided advance is thus represented when applied to the furnace or combustion engine arts or that pertaining to the distillation of liquids.

WhatI claim as my invention is 1. A rotary machine, comprising in combination a. casing formed with a cylinder, a transversely slotted rotor eccentrically arranged in said cylinder, a single vane member reciprocably mounted in the. slot in said rotor, said vane member having a transverse slotted portion extending beyond the cylinder, said vane member having axially spaced plane guide surfaces extending therefrom in right angular relation to the impeller axis, means engaging the opposite walls of said Slot beyond said cylinder to determine the reciprocal movement of the vane member in the rotor and guide means co-operatin with each of said axially spaced plane gui e surfaces to definitely maintain said im eller with its outer ends in true parallel relatlon to the cylinder wall.

2. A rotary machine, comprising a casing formed with a cylinder, a transversely slotted rotor eccentrically arranged in said cylinder, a single vane member reciprocably mounted in the slot in said rotor, bearing means for maintaining said vane member with its axis in true parallel relation to the rotor axis, and roller means operatively engaging said vane member at one end only of said cylinder for maintaining said vane in a neutral position in said cylinder, said bearing and roller means forming an active co-operation in controlling the position of said vane member.

3. A rotary machine, comprising a casin formed with a cylinder, a transversely slotte rotor eccentrically arranged in said cylinder, a single vane member reciprocably mounted in the slot in said rotor, rollermea'ns fixed to the cylinder casingat one end only of the cylinder in axial alignment with the cylinder axis operatively engaging said vane member at one side and supporting said member in a centralized position within said cylinder, and bearing means for maintaining said vane member with its axis in true parallel relation to the rotor axis in opposition to thrusts exerted by said single roller means.

4, A rotary machine, comprising a cylinder gaging said surfaces in rolling contact to relieve the vane from centrifugal thrust against the cylinder wall, said means forming a displacement pumping'member in said chamber.

5. A rotary machine, comprising a casing formed with a cylinder, a transversely slotted rotor eccentrically arranged in said cylinder,

a single vane member reciprocably mounted in the slot in said rotor, said vane member having a transversely extending bottomed slot formed therein, means closing the outer side ofsaid .slot and means mounted in a fixed position relative to said cylinder extending into said slot and engaging the walls thereof in rolling contact to mantain said vane member centralized in the cylinder, said means forming a'displacement pumping member in said set.

6. A rotary machine, comprising a casing A. A rotary machine comprising a inder, a single vane member reciprocably mounted in the slot in said rotor, a hub at one side of said vane havin a bottomed arallel-walled slot formed t erein exten ing in right-angular relation to the vane, a cap closing the outer end of said cylinder and slot, and a roller member mounted on said cap in. axial alignment with the cylinder axis and engaging the walls of said hub slot in rolling guiding contact, said roller fitting I snugly between the bottom of said slot and said cap and forming a displacement piston in the slot.

7. A rotary machine, comprising a casing formed with a cylinder, a transversely slotted rotor; eccentrically arranged in said cylinder, a single vane member reciprocably mounted in the slot in said rotor, a hub at one side of said vane externally of the cylinder having av parallel-walled slot formed therein extending in right-angular relation to the vane, a cap closing the outer end of said cylinder, a stub shaftrigidl secured in said cap in axial alignmentwitli the cylin der axis, a single roller bearing member mounted on and concentrically encircling said stub shaft and having its periphery engaging the walls of said,slotin progressive rolling thrust contact, and means co-operating with said vane member for maintaining its axis parallel to the rotor axis unaffected by thethrusts imposed on said vane member by said roller member. v

casing formed with a cylinder, a transversely slot- .ted rotor eccentrlcally arranged in said cylinder, a single vane member reciprocably mounted in the slot in said rotor, and having a guide portion disposed externally of the cylinder, a roller means disposed externally of the cylinder operatively "engaging said guide portion for maintaining said vane in a neutral position in said cylinder, and hearing means rigid with said vane member en gaging fixed bearing surfaces and supporting the vane against axial thrust.

9. A rotary machine, comprising a casing formed with a cylinder, a transversely slotted rotor eccentrically arranged in said cylinder, a single vane member reciprocably mounted in the slot in said rotor, guide means operatively engaging said vane member for maintaining said vane in a neutral position in said cylinder, a guide disc rigid with said vane member and, encircling said guide means and bearing means carried by said casing and engaging the side surfaces of said disc to support the vane against axial thrust, said guide disc and guide means be ing disposed in a substantially common lane at one side of the vane member whereby binding of said guide disc between said bearing means due to the thrusts exerted by said guide s ot, a guidedisc rigid means in neutralizin the vane is minimized.

10. A rotary mac ine, comprising a casing form d with a cylinder, a transversely slotted n ftor eccentrically arranged in said c linder, a vane reci rocable' in said rotor lycarried by said vane at the end of said rotor, a transverse slot in said disc, roller means engaging the walls of said slot to neutralize t e transverse position of said blade in the cylinder, and means carried by said cylinder casing engagingthe' faces of said guide disc to confine said vane against. thrust and displacement longitudinally in said. cylinder.

11. A rotary machine comprising a casing formed with a cylinder, a transversely slotted rotor eccentrically arranged in said cylinder, a vane reciiprocable in said rotor slot, a guide-disc rigi ly carried by said vane at the end of said rotor, a transverse slot in said disc, and means fixed to said casing in axiai"alignment with the cylinder axis engaging the walls of said disc slot in guiding contact to neutralize the transverse position ing formed with a cylinder, a transversely slotted rotor eccentrically arranged in said cylinder, a single vane member reciprocablymounted in the slot in said rotor, said vane member having a transverse slot formed therein, means mounted in a fixed position relative to said 0 linder and engaging the walls of said slot in rolling contact to maintain said vane member centralized in the cylinder, and stationary ports in the cylinder casing adapted to register periodically with the ends of said vane slot as the rotor rotates.

13. A rotary machine, comprisin a casing formed with a cylinder, a transverse y slotted rotor eccentrically arranged in said cylinder, a single vane member reciprocably mounted in the slot in said rotor, said vane member having a transverse slot formed therein,

means mounted ina fixed position relative to said cylinder and engaging the walls of said slot in rolling contact to maintain said vane rotor eccentrically arranged insaid cylinder:

a single vane member reciprocably mounted in theslot in said rotor, a hub at one side a of said vane having a parallel-walled slot formed therein extending in right-angular relation to the vane, a cap closing the outer rality of stationary ports in the wall of said cap arranged inoppositely disposed relation and extending in a path concentric with the cylinder axis, said oppositely arranged ports being adapted to communicate concurrently with the opposite ends of said guide slot.

15. A rotary machine, comprising a casing formed with a cylinder, a transversely slotted rotor eccentrically arranged in said cylinder, a single van member reciprocably mounted in the slot in said rotor, a hub at one side of said vane having a parallel-walled slot formed therein extending in right-angular relation to the vane, a cap closing the outer end of said cylinder, a roller member mounted on said cap in axial alignment with the cylinder axis and engaging the walls of said hub slot in rolling guiding contact, a peripheral tremities in true parallel relation to the cylguide flange carried by said hub and engaged on one side by saidcap member, and means carried by the casing engaging the other side of said guide flange, said flange supporting said vane with its end extremities in true parallel relation to the cylinderwalls.

16. A rotary machine, comprising a casing formed with a cylinder, a transversely slotted rotor eccentrically arranged in said cylinder, a vane-reciprocable in said rotor slot, a guide disc rigidly carried by said vane at the end of said rotor, a transverse slot in said disc, means fixed: to said casing in axial align- .ment with the cylinder axis engaging the walls of said disc slot in guiding contact to neutralize the transverse position of said vane in the cylinder, means carried by said cylinder casingfor engaging said disc on either side to definitely support the vane with its end exinder wall, ports in the cylinder casing, and

passages leading from the end walls of said guide-slot adapted to register with said ports.

17. A rotary machine, comprising a casing,

a cylinder formed in said casing at the outer end, a slotted rotor journalled in the inner end of said casing out of alignment with thecylinder axis and arranged in said cylinder, a vane reciprocably mounted in the slot of said rotor and co-operating at each end with the cylinder wall, acap closing the outer end of said cylinder, said cap having a depressed inward portion, a guide disc rigidly carried by said vane and extending into the depressed portion of said cap and having its end face snugly engaging the end wall thereof, an annular bearing ring secured between said casing and cap and snugly engaging said disc on its inner side, and means carried by said cap co-operating with said guide disc for maintaining said vane in'longitudinal central- 05 'ized relation to the cylinder walls.

' 18. --A rotary machine, comprising a casing, a cylinder formed in said casing at the outer end, a slotted rotor journalled in the inner end of said casing out of alignment with the cylinder axis and arranged in said cylinder, a vane reciprocably mounted in the slot of said rotor and co-operating at each end with the cylinder wall, a cap closing the outer end of said cylinder, said cap having a depressed inward portion presenting a plane wall in right angular relation to the cylinder axis, a guide disc rigidly carried by said vane and disposed in said cap depression said plane wall engaging the outer surface of said disc in guiding contact, bearing means engaging the inner side of said disc in guiding contact, a diametrical slot in the outer face of said guide disc in disposed right-angular relation to said vane, guiding means fixed to said cap and extending into said diametrical slot in said disc and engaging the opposite side walls thereof,

and paired arc-shaped ports arranged inthe wall of said cap depression.

19. A rotary machine, comprising a casing, a cylinder formed in said casing at the outer end,-a slotted rotor journalled in the inner end of said casing ,out of alignment with the cylinder axis and arranged in said cylinder, a vane reciprocably mounted in the slot of said rotor and co-operating at each end with the cylinder'walL-a cap closing the outer end of said vcylinder, said cap having a centrally depressed inward portion presenting a plane wall in right angular re-- lation to the cylinder axis, a guide disc rigid with said vane and disposed within said cap depression said plane wall engaging the outer surface of said disc in guiding contact, bearing means engaging the inner side of said disc in guiding contact, a diametrical slot in the outer face of said guide disc'in disposed right-angular relation to said vane, astub shaft fixed rigidly in said cap and extending inwardly into said guide slot, a roller bearing mounted on said stub shaft and snugly engaging the side walls of said guide slot in rolling guiding contact, a pair of said cap and arranged one on each side of a line passing through the rotor and cylinder axes, and ports in said disc leading from the outer ends of said guide slot and adapted to register with said arc-shaped ports.

20. A rotary machine, comprising a'casing bored at one end to form a cylinder, a bearing arranged in the other end of said casing in eccentric relation to'the cylinder axis and parallel therewith, an annular recess in the outer end of the cylinder wall, a slotted rotor concentrically journalled in said bearing and disposed in said cylinder, a vane in the slot of said rotor having a guide disc integral therewith and arranged at the outer side of said rotor, an annular bearing ring arranged in said cylinder wall recess and extending inwardly between said rotor and disc and engaging the latter in guiding contact, and a cap closing the outer end of said cylinder and having an annular flange entering the annular recess of said cylinder wall and securing said annular bearing ring therein, the inner wall of said cap engaging the outer surface of said guide disc in bearing contact.

21. A rotary machine, comprising a casing bored at one end to form a cylinder, a bearing arranged in the other end of said casing in eccentric relation to the cylinder axis and parallel therewith, an annular recess in the outer end of the cylinder wall, a slotted rotor concentrically journalled in said bearing and disposed in said cylinder, a vane in the rotor slot, a cap closing the outer end of said cyl- 29 inder, means supported by said cap for supporting said vane in a centralized position in said cylinder with its ends in true parallel relation to the cylinder wall, a drive shaft extending into said casing concentric with said bearing and operatively connected with said rotor, an internally grooved ring member carried by said casing and encircling the drive shaft, and a passage leading from said ring groove to the intake of said cylinder. 8o .22. A rotary machine, comprising a casing having a cylinder chamber at one end closed by a cap member at the outer end, a drive shaftextending into the casing from the other end in parallelly ofi'set relation to the cylinder axis, the'inner wall of said cylinder having stepped recesses a bearing fitting in one of said recesses, a rotor having a portion thereof extending into the other recess and having a sleeve extension concentrically en- 40 circling said drive shaft and supported in saidbearing, said rotor being slotted,-a vane reciprocably mounted in the rotor slot, and means supported by said cap member for guiding said vane against lateral and transverse thrust.

23. A rotary machine, comprising a casing formed with a cylinder, a transversely slotted rotor eccentrically arranged in said cylinder, a single vane member reciprocably mounted ISO in the slot in said rotor, said vane having guide surfaces right-singularly arrange with relation. thereto, and extending beyond the true cylinder cavity, rotatable guide means mounted in a fixed position anden- 65' gaging certain of said right-angularly arranged surfaces in rolling contact to maintain said vane in a neutral position in said cylinder, and secondary guide means 'co-' operating with the other of said right-angularly arranged surfaces to maintain said vane with its outer ends in true parallel relation to the cylinder wall. '7

v WILLIAM E. SHORE. 

